1. Field of the Invention
The present invention relates, generally, to a method of making a vehicle seat and, more specifically, to a method of making a vehicle seat crossmember.
2. Description of the Related Art
Seats for motor vehicles are well known and produced in a wide variety of styles and types. Seat construction also varies widely. For example, it is common to provide a one-piece seat pan to support the lower seat cushion structure of the bottom of a vehicle seat. This is particularly true with sport utility and smaller sized vehicles that employ separate or bucket-style front seating arrangements. However, in larger vehicles and in vehicles with wider seat construction, a more substantial frame consisting of several elements is employed to support the larger lower seat cushion. These multi-piece seat frames are also employed for mid and/or rear vehicle seating arrangements where the seat spans the vehicle or is split to fold in portions.
Due to economic factors, vehicle and vehicle seat manufacturers are constantly under pressure to reduce the weight of vehicle seats while maintaining their structural strength. Production and manufacturing costs are also scrutinized. Lighter weight materials in the vehicle seat can lower the cost of manufacturing by reducing the amount of materials used, and generally lower the operating expense of the vehicle by contributing toward improving the gas mileage. On the other hand, more efficient production methods also provide cost savings. More specifically, cost savings can be realized if the number of production or process steps are reduced or if a process can be re-engineered so that less human intervention and a greater number of machine controlled operations are utilized instead.
In a multi-piece seat frame, the rear crossmember is generally key to providing the majority of structural integrity for the entire seat. The rear crossmember must not only support the lower seat cushion but also the seat back as well. Often, the seat is secured to the floor by the rear crossmember such that the rear crossmember also takes on the seat belt loading in an emergency situation. In conventional multi-piece vehicle seats, the rear crossmember tends to be a heavy and generally complex element. Rear crossmembers are constructed of two or more pieces that are separately stamped and then welded together. Conventional rear crossmembers must also have openings cut and fasteners installed that are later used during seat build up and installation of the seat assembly in the vehicle. The placement and securing of the fasteners in the conventional crossmembers requires that nuts be placed and welded individually on the inside of one of the stamped sections before the rear crossmember is assembled. Thus, current construction methods require a considerable number of steps and separate processes to arrive at the completed rear crossmember. Additionally, a number of these steps require human intervention and control to produce this product. The large number of production steps as well as the requirement for human intervention makes these components expensive and time consuming to produce
Thus, there remains a need in the art for a process that produces a lightweight, yet strong, single piece rear crossmember for a vehicle seat that is economical to produce and does not require human intervention during the manufacturing process.